Comparison of Midline Splitting versus Unilateral Open Door Laminoplasty and Its Impact on Patient Outcomes

Background@#Laminoplasty is a common and effective surgery for decompression of the spinal cord in multilevel cervical myelopathy. The midline splitting technique (MST) and the unilateral open door technique (UODT) are the two most commonly performed laminoplasty techniques with continuous debate on which is preferable. This study aimed to add light to the matter by comparing and exploring the possible causes of different outcomes. @*Methods@#A total of 101 patients who underwent laminoplasty for degenerative cervical myelopathy were included in this study.Radiographic measurements including C2–7 Cobb angle, C2–7 range of motion (ROM), Pavlov ratio of the most compressed level, and canal area with diameter were compared. Modified Japanese Orthopedic Association (mJOA) score and complications including C5 palsy, axial neck pain, hinge fractures, and spacer displacement were also compared. Statistical analysis was performed using independent samples t-test, chi-square test, Fisher’s exact test, and linear mixed model. @*Results@#C2–7 ROM, canal diameter, Pavlov ratio, and mJOA score did not demonstrate differences between the two techniques.The UODT group had greater postoperative canal expansion but had more loss of C2–7 lordosis than did the MST group. Of the complications, hinge fractures were more common in the UODT group, with more loss of C2–7 lordosis in patients with hinge fractures. On the other hand, spacer displacement occurred only in the MST group, with lesser canal expansion in patients with spacer displacement. @*Conclusions@#The two laminoplasty techniques both demonstrated effectiveness in treating patients with multilevel cervical myelopathy. However, care should be given to avoid hinge fractures and spacer displacement since both can possibly lead to unfavorable outcomes.

Hypoxia Regulates the Extracellular Matrix via Mitogen-Activated Protein Kinases Pathway in Cells Retrieved from the Human Intervertebral Disc

Purpose@#The present study aimed to identify the physiological characteristics of cells by investigating the change in gene expression and protein levels during extracellular matrix (ECM) synthesis in the intervertebral disc (IVD) under hypoxic conditions. @*Materials and Methods@#To test the effect of oxygen on cell growth and ECM synthesis of chondrocyte-like cells, the cells from IVD were separated and cultured in two hypoxia-mimicking systems: chemical hypoxic conditions using deferoxamine (DFO), and physiological hypoxic conditions using a hypoxic chamber for 7 days. Chondrocyte like cells cultured without DFO and under the normal oxygen concentration (21% O2 and 5% CO2, 37°C) served as the controls. @*Results@#Chondrocyte-like cells cultured in the presence of 6% oxygen demonstrated a 100% increase in cellular proliferation compared to the control. The cells treated with chemical hypoxic conditions demonstrated a dose-dependent increase in the mRNA expression of glucose transporter-1, GAPDH, aggrecan, and type II collagen on Day 1. When treated with 100 μM DFO, the cells showed a 50% increase in the levels of proteoglycan protein on Day 7. The cells treated with chemical hypoxic condition demonstrated increase in sulfated glycosaminoglycan (GAG) protein levels on Day 7. Moreover, the cells cultured in the presence of 6% oxygen showed a 120% increase in sulfated GAG levels on Day 7. @*Conclusion@#The oxygen concentration had an important role in the viability, proliferation, and maturation of chondrocyte-like cells in IVD. In addition, chondrocyte-like cells are sensitive to the concentration of oxygen.

Hypoxia Regulates the Extracellular Matrix via Mitogen-Activated Protein Kinases Pathway in Cells Retrieved from the Human Intervertebral Disc

Purpose@#The present study aimed to identify the physiological characteristics of cells by investigating the change in gene expression and protein levels during extracellular matrix (ECM) synthesis in the intervertebral disc (IVD) under hypoxic conditions. @*Materials and Methods@#To test the effect of oxygen on cell growth and ECM synthesis of chondrocyte-like cells, the cells from IVD were separated and cultured in two hypoxia-mimicking systems: chemical hypoxic conditions using deferoxamine (DFO), and physiological hypoxic conditions using a hypoxic chamber for 7 days. Chondrocyte like cells cultured without DFO and under the normal oxygen concentration (21% O2 and 5% CO2, 37°C) served as the controls. @*Results@#Chondrocyte-like cells cultured in the presence of 6% oxygen demonstrated a 100% increase in cellular proliferation compared to the control. The cells treated with chemical hypoxic conditions demonstrated a dose-dependent increase in the mRNA expression of glucose transporter-1, GAPDH, aggrecan, and type II collagen on Day 1. When treated with 100 μM DFO, the cells showed a 50% increase in the levels of proteoglycan protein on Day 7. The cells treated with chemical hypoxic condition demonstrated increase in sulfated glycosaminoglycan (GAG) protein levels on Day 7. Moreover, the cells cultured in the presence of 6% oxygen showed a 120% increase in sulfated GAG levels on Day 7. @*Conclusion@#The oxygen concentration had an important role in the viability, proliferation, and maturation of chondrocyte-like cells in IVD. In addition, chondrocyte-like cells are sensitive to the concentration of oxygen.

Comparison of the Prevalence of Low Back Pain and Related Spinal Diseases among Smokers and Nonsmokers: Using Korean National Health Insurance Database

Background@#To compare the risk of low back pain (LBP) and related spinal diseases between smokers (exposure group) and nonsmokers (non-exposure group). No large registry study has so far investigated the association between smoking and LBP-related spinal diseases such as intervertebral disc disease, spinal stenosis, spinal instability, and spondylolisthesis. @*Methods@#A random sample was taken from the Korean National Health Insurance Research Database. In total, 204,066 men (160,105 smokers, 43,961 nonsmokers) who were followed up between 2002 and 2013 were included in the analysis. Patients with previous back pain or spinal disease in 2003 and 2004, patients with inappropriate data, and women (due to the lower percentage of smokers) were excluded. The Cox proportional hazard model was used to investigate the risk of LBP and related spinal diseases associated with smoking, while adjusting for demographic, clinical, and socioeconomic factors. @*Results@#The overall median follow-up period was 5.6 years (interquartile range, 3.48–8.43 years). Compared to the nonsmoker group, the smoker group had a higher incidence of LBP (p = 0.01), intervertebral disc disease (p < 0.001), spinal stenosis (p = 0.004), spinal instability (p < 0.001), and spondylolisthesis (p = 0.023). Compared to the nonsmoker group, the smoker group had a higher adjusted hazard ratio (HR) per year of LBP (HR, 1.18; 95% confidence interval [CI], 1.15 to 1.21), intervertebral disc disease (HR, 1.25; 95% CI, 1.21 to 1.30), spinal stenosis (HR, 1.52; 95% CI, 1.41 to 1.64), spinal instability (HR, 1.33; 95% CI, 1.24 to 1.44), and spondylolisthesis (HR, 1.49; 95% CI, 1.23 to 1.80). @*Conclusions@#Smokers in male samples were at higher risk for LBP and related spinal diseases than nonsmokers.

Prevalence of Gastrointestinal and Cardiovascular Risk in Patients with Degenerative Lumbar Spinal Disease

Background@#Limited information is available about the proportion of patients with degenerative lumbar spinal disease (DLSD) who have gastrointestinal (GI) and cardiovascular (CV) risk factors. Many DLSD patients are prescribed nonsteroidal anti-inflammatory drugs (NSAIDs) that are known to carry risks to the GI and CV systems by increasing GI bleeding and thromboembolic events.This study aimed to measure the prevalence of GI and CV risk in patients with DLSD and to ascertain whether the prescription of NSAIDs is in line with current guidelines. @*Methods@#This study included 153 patients with symptomatic DLSD who were planning to undergo lumbar spinal surgery. The GI profile was checked using the GI Standardized Calculator of Risk for Event system and CV risk was evaluated using the presence of metabolic syndrome. The conformity of the prescription of NSAIDs was investigated according to the recommendations in current guidelines. @*Results@#More than half of the patients (59.5%) had high or very high GI risk, and 66% of the patients were diagnosed with metabolic syndrome, which corresponds with CV risk. The rate of simultaneous GI and CV risk was 40.5% (n = 62 / 153; gastrointestinal Standardized Calculator of Risk for Event, > high and metabolic syndrome, yes). The actual prescription of NSAIDs was not in accordance with current guidelines. @*Conclusions@#Two out of 3 patients had GI or CV risk factors, and approximately 40% of patients had both. Detailed assessment of GI and CV risk in patients with DLSD by using effective evaluation tools is mandatory for optimal medical treatment.

Comparison of Disc Degeneration between the Cervical and Lumbar Spine

Objectives@#To compare disc degeneration between the cervical and lumbar spine and to elucidate the patterns of degeneration according to the corresponding disc levels in the cervical and lumbar spine.Summary of Literature Review: Disc degeneration results from the aging process in the spine. However, the incidence of disc degeneration in the cervical and lumbar spine might differ due to anatomical differences @*Materials and Methods@#We randomly selected 280 patients by age and sex among 6,168 patients who underwent cervical or lumbar spine magnetic resonance imaging combined with whole-spine T2 sagittal images from June 2006 to March 2012. We classified disc degeneration by the modified Matsumoto grading system and the Pfirrmann classification at 11 intervertebral disc levels from C2 to T1 and from L1 to S1. @*Results@#There was no significant difference in disc degeneration between the cervical and lumbar spine in either grading system. No significant difference was found in the degree of disc degeneration between the lower two disc levels of the cervical spine and the lower two disc levels of the lumbar spine in either system (C5-C6, C6-C7, L4-L5, L5-S1). However, both grading systems showed more severe degeneration in upper two disc levels of the cervical spine than in the upper two disc levels of the lumbar spine (C2-C3, C3-C4, L1-L2, L2- L3). @*Conclusions@#There was a significant difference in disc degeneration between the upper two disc levels of the cervical and lumbar spine. Adjacent segmental degeneration after fusion surgery might reflect the natural history of the condition, not adjacent segmental problems.

Lumbar Spinal Stenosis: Pathophysiology and Treatment Principle: A Narrative Review

Patients with lumbar spinal stenosis may exhibit symptoms such as back pain, radiating pain, and neurogenic claudication. Although long-term outcome of treatments manifests similar results for both nonsurgical and surgical treatments, positive effects such as short-term improvement in symptoms and decreased fall risk may be expected with surgery. Surgical treatment is basically decompression, and a combination of treatments can be added depending on the degree of decompression and the accompanying instability. Recently, minimally invasive surgery has been found to result in excellent outcomes in the treatment of lumbar spinal stenosis. Therefore, better treatment effects can be anticipated with an approach aimed at understanding the overall pathophysiology and treatment methods of lumbar spinal stenosis.

Follistatin Mitigates Myofibroblast Differentiation and Collagen Synthesis of Fibroblasts from Scar Tissue around Injured Flexor Tendons

Arthrodesis Using Bilateral Dual Iliac Screws with Autologous Iliac Bone Transfer for the Treatment of Pyogenic Sacroiliitis

Results of Magnetically Controlled Growing Rods for Early Onset Scoliosis / 대한정형외과학회잡지

PURPOSE: To evaluate the first results of surgical treatment using newly developed magnetically controlled growing rods (MCGR) for early onset scoliosis (EOS). MATERIALS AND METHODS: From January 2013 to January 2017, 5 patients, who underwent surgical treatment with MCGR for EOS and were followed for more than one year, were analyzed retrospectively. The demographic and radiology data, including age at surgery, diagnosis, number of lengthening, Cobb angle, T1–S1 length, T1–T12 length, and complications, were analyzed. RESULTS: The mean age of the patients was 6.0±2.7 years old. The subjects were 3 males and 2 females: 2 with neuromuscular scoliosis, 1 with syndromic scoliosis, 1 with idiopathic scoliosis, and 1 with congenital scoliosis. The mean number of lengthening was 9.8±2.9 times and the follow-up was 21.6±5.7 months. The Cobb angle improved from 82.0°±28.5° to 48.3°±28.8° at the last follow-up. The T1–S1 length increased from 283.1±72.7 mm to 342.6±86.3 mm at the last follow-up. The T1–T12 length increased from 163.1±50.5 mm to 202.3±65.5 mm at the last follow-up. One screw loosening complication was encountered and there were no neurological complications. CONCLUSION: The treatment using MCGR for EOS is effective and useful.

Analgesic Efficacy and Safety of Prolonged-Release Oxycodone/Naloxone in Korean Patients with Chronic Pain from Spinal Disorders

BACKGROUND: A prolonged-release formulation of oxycodone/naloxone has been shown to be effective in European populations for the management of chronic moderate to severe pain. However, no clinical data exist for its use in Korean patients. The objective of this study was to assess efficacy and safety of prolonged-release oxycodone/naloxone in Korean patients for management of chronic moderate-to-severe pain. METHODS: In this multicenter, single-arm, open-label, phase IV study, Korean adults with moderate-to-severe spinal disorder-related pain that was not satisfactorily controlled with weak opioids and nonsteroidal anti-inflammatory drugs received prolonged-release oral oxycodone/naloxone at a starting dose of 10/5 mg/day (maximum 80/40 mg/day) for 8 weeks. Changes in pain intensity and quality of life (QoL) were measured using a numeric rating scale (NRS, 0–10) and the Korean-language EuroQol-five dimensions questionnaire, respectively. RESULTS: Among 209 patients assessed for efficacy, the mean NRS pain score was reduced by 25.9% between baseline and week 8 of treatment (p < 0.0001). There was also a significant improvement in QoL from baseline to week 8 (p < 0.0001). The incidence of adverse drug reactions was 27.7%, the most common being nausea, constipation, and dizziness; 77.9% of these adverse drug reactions had resolved or were resolving at the end of the study. CONCLUSIONS: Prolonged-release oxycodone/naloxone provided significant and clinically relevant reductions in pain intensity and improved QoL in Korean patients with chronic spinal disorders. (ClinicalTrials.gov identifier: NCT01811238)

Effect of Sagittal Balance on Risk of Falling after Lateral Lumbar Interbody Fusion Surgery Combined with Posterior Surgery

PURPOSE: To demonstrate the impact of correcting sagittal balance (SB) on functional outcomes of surgical treatment for degenerative spinal disease and actual falls via utilization of new minimally invasive lumbar fusion techniques via a lateral approach. MATERIALS AND METHODS: From November 2011 to March 2015, we enrolled 56 patients who underwent minimally invasive lateral lumbar interbody fusion (LLIF) and matched 112 patients receiving decompression/postero-lateral fusion (PLF) surgery for lumbar spinal stenosis. According to SB status using C7-plumb line-distance (C7PL) and surgery type, patients were divided into three groups: SB PLF, sagittal imbalance (SI) PLF, and LLIF groups. We then compared their outcomes. RESULTS: The mean C7PL was 6.2±13.6 mm in the SB PLF group, 72.9±33.8 mm in the SI PLF group, and 74.8±38.2 mm in the LLIF group preoperatively. Postoperatively, C7PL in only the LLIF group improved significantly (p=0.000). Patients in the LLIF group showed greater improvement in fall-related functional test scores than the SI PLF group (p=0.007 for Alternate-Step test, p=0.032 for Sit-to-Stand test). The average number of postoperative falls was 0.4±0.7 in the SB PLF group, 1.1±1.4 in the SI PLF group, and 0.8±1.0 in the LLIF group (p=0.041). Oswestry Disability Index and the Euro-QoL 5 dimension visual analogue scale scores also showed greater improvements in the LLIF group than in the SI PLF group at postoperative 1 year (p=0.003, 0.016). CONCLUSION: Surgical correction of SI in patients with lumbar spinal stenosis using a combination of minimal invasive LLIF and posterior surgery achieved better surgical outcomes and a lower incidence of actual falls than PLF surgery.

Efficacy and Safety of Different Aceclofenac Treatments for Chronic Lower Back Pain: Prospective, Randomized, Single Center, Open-Label Clinical Trials

PURPOSE: Nonsteroidal anti-inflammatory drugs are a mainstay for medical treatment of chronic lower back pain (CLBP). Increased dose intervals for medication have been associated with increased patient adherence to prescriptions. The purpose of this clinical trial was to compare the efficacy and safety of a once daily dose of aceclofenac controlled release (CR) and a twice daily dose of aceclofenac for CLBP management. MATERIALS AND METHODS: A prospective, randomized, single center, open-label clinical trial was performed to compare the efficacy and safety of aceclofenac CR (200 mg once daily) to aceclofenac dose (100 mg twice daily). Fifty patients in each group were enrolled for the study. The primary end point was Visual Analogue Scale (VAS) change at baseline to that at 2 weeks after medication and safety profiles. Also, change in quality of life measured by EuroQoL 5D (EQ-5D) and Oswestry Disability Index (ODI) functional score for the lumbar spine were also assessed. RESULTS: Within groups at pre- and post-treatment, there were significant VAS reductions for aceclofenac CR and aceclofenac (p=0.028). EQ-5D increased significantly in both groups (p=0.037). ODI scores decreased significantly in both groups (p=0.012). However, there were no significant differences between aceclofenac CR and aceclofenac at pre- and post-treatment. Patients with aceclofenac CR showed significant increases in heartburn and indigestion and adverse gastrointestinal effects, compared to aceclofenac. CONCLUSION: In patients with CLBP, aceclofenac CR and aceclofenac demonstrated significant symptomatic pain relief, improvement in quality of life and functional scores. Aceclofenac CR slightly increased gastrointestinal adverse effects, such as heartburn and indigestion.

Relaxin Modulates the Expression of MMPs and TIMPs in Fibroblasts of Patients with Carpal Tunnel Syndrome

PURPOSE: The aim of this study was to investigate the anti-fibrotic effect of relaxin in subsynovial fibroblasts activated by transforming growth factor beta (TGF-β). MATERIALS AND METHODS: To test the anti-fibrotic effect of an adenovirus-relaxin construct (Ad-RLN) on subsynovial fibroblasts in vitro, cells from subsynovial connective tissue of patients with carpal tunnel syndrome were activated with TGF-β1 and exposed to Ad-RLN (as a therapeutic gene) or adenovirus-lacZ construct (as a marker gene) for four hours. Subsynovial fibroblast cultures without adenoviral exposure served as controls. RESULTS: We observed induction of gene expressions of collagen I, III and IV, as well as the abatement of alpha-smooth muscle actin (a-SMA) synthesis, Smad2 phosphorylation, and fibronectin at the protein level, in comparison to controls. In addition, protein expressions of matrix metalloproteinase (MMP) I was significantly induced, whereas the protein expressions of tissue inhibitor of metalloproteinases (TIMP) I and IV were reduced due to relaxin expression. CONCLUSION: RLN prevents excessive synthesis of extracellular matrix by reducing the expressions of its components, such as fibronectin, a-SMA, and phosphorylated Smad2, by increasing the expression of MMPs; and by decreasing the expression of TIMPs.

Dual Growing Rod Treatment for Progressive Pediatric Spinal Deformity

STUDY DESIGN: Retrospective study. OBJECTIVES: To evaluate the outcomes of dual growing rod treatment over a follow-up period of at least 2 years in patients with progressive pediatric spinal deformity. SUMMARY OF LITERATURE REVIEW: The dual growing rod treatment is safe and effective in curve correction and maintenance in patients with progressive pediatric spinal deformity. MATERIALS AND METHODS: Between 2009 to 2017, 14 patients who underwent dual growing rod treatment were followed up for more than 2 years. We analyzed their demographic and radiologic data, including age at surgery, sex, diagnosis, instrumented levels, number of total operations, number of lengthening procedures, interval of lengthening, Cobb angle, thoracic kyphosis angle, lumbar lordosis angle, T1-S1 length, and complications. RESULTS: The mean age of the patients was 11.0±2.9 years old. There were 10 male and 4 female patients, including 8 cases of neuromuscular scoliosis, 3 cases of idiopathic scoliosis, 2 cases of spondyloepiphyseal dysplasia, and 1 case of congenital scoliosis. The mean follow-up period was 42.4±14.0 months. The total number of operations was 6.6±2.6. The average number of lengthening procedures was 4.3±2.3 at an interval of 6.9±2.1 months. The Cobb angle improved from 60.4°±27.9° to 33.5°±19.7° after the initial treatment and 29.1°±16.4° after the last follow-up or final fusion. The T1-S1 length increased from 328.2±57.5 mm to 388.0±64.9 mm after the initial treatment and 424.9±64.4 mm after the last follow-up or final spinal fusion. The average growth rate was 11.5 mm/year. Six patients experienced 11 complications, of which 4 were Implant-related, and 7 were Infections. CONCLUSIONS: The dual growing rod technique is an effective and relatively safe treatment in patients with progressive pediatric spinal deformity.

Surgical Anatomy of the Longus Colli Muscle and Uncinate Process in the Cervical Spine

PURPOSE: There have been a few previous reports regarding the distances between the medial borders of the longus colli to expose the disc space. However, to our knowledge, there are no reports concerning longus colli dissection to expose the uncinate processes. This study was undertaken to assess the surgical relationship between the longus colli muscle and the uncinate process in the cervical spine. MATERIALS AND METHODS: This study included 120 Korean patients randomly selected from 333 who had cervical spine MRIs and CTs from January 2003 to October 2013. They consisted of 60 males and 60 females. Each group was subdivided into six groups by age from 20 to 70 years or more. We measured three parameters on MRIs from C3 to T1: left and right longus colli distance and inter-longus colli distance. We also measured three parameters on CT: left and right uncinate distance and inter-uncinate distance. RESULTS: The longus colli distances, uncinate distances, and inter-uncinate distances increased from C3 to T1. The inter-longus colli distances increased from C3 to C7. There was no difference in longus colli distances and uncinate distances between males and females. There was no difference in the six parameters for the different age groups. CONCLUSION: Although approximate guidelines, we recommend the longus colli be dissected approximately 5 mm at C3-5, 6 mm at C5-6, 7 mm at C6-7, and 8 mm at C7-T1 to expose the uncinate process to its lateral edge.

Research Support Programs of the National Research Foundation of Korea

STUDY DESIGN: Literature review. OBJECTIVES: The aim of this study was to present updated information on the research support programs offered by the National Research Foundation of Korea. SUMMARY OF LITERATURE REVIEW: The research support programs offered by the National Research Foundation of Korea are an important cornerstone for obtaining other grants from the government and commercial companies. However, no information has yet been provided in the literature about these programs. MATERIALS AND METHODS: Review of the relevant literature. RESULTS: The research support programs offered by the National Research Foundation of Korea are complex. However, it is possible to find appropriate grants. It is necessary to focus on the individual basic research program. CONCLUSIONS: Novel proposals have a greater chance of receiving funding, especially if the appropriate background and preliminary data are provided.

Whiplash Injury

STUDY DESIGN: Review of the literature. OBJECTIVES: To present an overview of current research on whiplash injury. SUMMARY OF LITERATURE REVIEW: There are controversies over the definition, symptoms, and treatment of whiplash injury. MATERIALS AND METHODS: Review of the relevant literature. RESULTS: Symptoms of whiplash injury caused by an acceleration-deceleration force may present as widespread pain involving the neck or trapezius muscles, the interscapular area, the shoulders and arms, or as suboccipital headaches. Accompanying symptoms may include neurologic symptoms such as sensory dysfunction, motor weakness, or deep tendon reflex loss; non-specific symptoms such as dysphagia, dizziness, visual disturbances, tinnitus, deafness, memory loss, or temporo-mandibular joint disorders; and psychological symptoms such as depression, acute stress syndrome, or fear avoidance. The most important factor that facilitates spontaneous resolution of whiplash injury, which is a self-limiting disorder, has been shown to be prevention of the acute-to-chronic pain transition. Yet in spite of this knowledge the efficacy of several treatment methods for whiplash injury remains controversial. CONCLUSIONS: The appropriateness of treatment for whiplash injury should be evaluated on the basis of up to date academic research on its diagnosis and natural history.

Effect of Smoking on Osteoporotic Vertebral Fracture in Postmenopausal Women

STUDY DESIGN: A retrospective study. OBJECTIVES: To evaluate the association between smoking and osteoporotic vertebral fractures (OVFs) in postmenopausal women. SUMMARY OF LITERATURE REVIEW: Several studies have examined the relationship of smoking with hip fractures, but few studies have analyzed the relationship of smoking with spine fractures in women thus far. MATERIALS AND METHODS: This study considered 1255 postmenopausal women aged 50 years and older (enrollment from April 2008 to January 2009) from 62 study sites in a nationwide hospital. The amount of smoking was calculated in pack-years. Further, OVFs were diagnosed using a semi-quantitative method. To analyze the relationship between smoking and OVFs, we used a paired t-test, a χ2-test, and a binary logistic regression analysis. RESULTS: The past history of smoking was 7.2% in the patient group and 4.3% in the control group (p=0.025). The mean pack-years of smoking was 0.34 in the control group and 0.62 in the patient group (p=130). The mean T-score in the lumbar bone mass density (BMD) was –1.64 in the control group and –2.19 in the patient group (p=0.409). Smoking was a risk factor of vertebral fractures in postmenopausal women (odd's ratio=1.68, 95% confidence interval=1.020–2.759, p=0.042) irrespective of the lumbar BMD and the medical treatment for osteoporosis and obesity. CONCLUSIONS: Smoking is a risk factor for osteoporotic vertebral fractures in postmenopausal women independently without regard to lumbar BMD. Therefore, cessation of smoking is important for the prevention of OVFs in postmenopausal women.

New Radiographic Index for Occipito-Cervical Instability

STUDY DESIGN: Retrospective study. PURPOSE: To propose a new radiographic index for occipito-cervical instability. OVERVIEW OF LITERATURE: Symptomatic atlanto-occipital instability requires the fusion of the atlanto-occipital joint. However, measurements of occipito-cervical translation using the Wiesel-Rothman technique, Power's ratio, and basion-axial interval are unreliable because the radiologic landmarks in the occipito-cervical junction lack clarity in radiography. METHODS: One hundred four asymptomatic subjects were evaluated with lateral cervical radiographs in neutral, flexion and extension. They were stratified by age and included 52 young (20-29 years) and 52 middle-aged adults (50-59 years). The four radiographic reference points were posterior edge of hard palate (hard palate), posteroinferior corner of the most posterior upper molar tooth (molar), posteroinferior corner of the C1 anterior ring (posterior C1), and posteroinferior corner of the C2 vertebral body (posterior C2). The distance from posterior C1 and posterior C2 to the above anatomical landmarks was measured to calculate the range of motion (ROM) on dynamic radiographs. To determine the difference between the two age groups, unpaired t-tests were used. The statistical significance level was set at p<0.05. RESULTS: The ROM was 4.8+/-7.3 mm between the hard palate and the posterior C1, 9.9+/-10.2 mm between the hard palate and the posterior C2, 1.7+/-7.2 mm between the molar to the posterior C1, and 10.4+/-12.1 mm between the molar to the posterior C2. There was no statistically significant difference for the ROM between the young- and the middle-aged groups. The intra-observer reliability for new radiographic index was good. The inter-observer reliability for the ROM measured by the hard palate was low, but was better than that by the molar. CONCLUSIONS: ROM measured by the hard palate might be a useful new radiographic index in cases of occipito-cervical instability.